This article explores experiences of environmental activism from the viewpoint of members of a radical environment group. It is based on data collected during eight months of participant observation and through semistructured interviews with ten core members and two ex-members. Working on personal feelings, attitudes, beliefs, and behaviors (self-work) was central to the strategy for social change employed by this group. Drawing on Weber's sociology of religion, this article explores the way the high expectation the activists had of themselves matched Weber's typification of the rationally active ascetic. It is argued that asceticism is an enduring element of Western culture that takes different forms in response to historical conditions. In this case, we see a form of secular asceticism that responds to the conditions of late modernity